Valdemoro told GMA News Online in a phone interview that they changed the code from Green to Orange after receiving feedback from the public that the codes cause confusion.

"The research group deemed Orange is more appropriate to denote the varying intensity of the rain," said Valdemoro.

PAGASA devised a three-level Rainfall Warning System, currently in operation for Metro Manila, to alert the public of the intensity of the rainfall and inform them of any possible flood or other hazards brought about by the precipitation.

The original colors assigned for warning were Yellow for monitoring; Green for alert; and Red for evacuation.

The new colors now are:

Yellow: indicates 7.5 to 15 mm (heavy) rain in the last hour and likely in the next two hours, and possible flooding. The public is asked to monitor weather conditions.

Orange: indicates 15 to 30 mm (intense) rain in the last hour and likely in the next two hours, and that flooding is "threatening." The public is asked to be alert for possible evacuation.

Red: indicates more than 30 mm of rain in the last hour and likely in the next two hours, and that serious flooding in low-lying areas may occur. The public is asked to evacuate.

When the system with the Green warning was introduced, it raised questions from some netizens who said it may cause confusion among those familiar with the red-yellow-green traffic light system.

"As it is in traffic, yellow should be between green and red. Don't sow confusion by rearranging long-held constants," tweeted columnist Federico Pascual.

The Rainfall Warning System is part of the two-phase program of PAGASA to improve its weather alerts. –KG/HS, GMA News